diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
index 0aa984dc0..a8d97986e 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
@@ -191,7 +191,7 @@ public class SnifferConfigInitializer {
      * <p>
      * such as: Property key of `agent.service_name` should be `skywalking.agent.service_name`
      */
-    private static void overrideConfigBySystemProp() throws IllegalAccessException {
+    private static void overrideConfigBySystemProp() {
         Properties systemProperties = System.getProperties();
         for (final Map.Entry<Object, Object> prop : systemProperties.entrySet()) {
             String key = prop.getKey().toString();
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/logging/core/JsonLogger.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/logging/core/JsonLogger.java
index cffd49313..c81e8b11d 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/logging/core/JsonLogger.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/logging/core/JsonLogger.java
@@ -71,7 +71,7 @@ public class JsonLogger extends AbstractLogger {
     @Override
     protected String format(LogLevel level, String message, Throwable e) {
         LogEvent logEvent = new LogEvent(level, message, e, this.targetClass);
-        Map<String, String> log = new HashMap<>();
+        Map<String, String> log = new HashMap<>(this.converters.size());
         for (Converter converter : this.converters) {
             log.put(converter.getKey(), converter.convert(logEvent));
         }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java
index 81736eea9..3c545d80f 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java
@@ -63,6 +63,7 @@ public abstract class ClassEnhancePluginDefine extends AbstractClassEnhancePlugi
      * @param newClassBuilder byte-buddy's builder to manipulate class bytecode.
      * @return new byte-buddy's builder for further manipulation.
      */
+    @Override
     protected DynamicType.Builder<?> enhanceInstance(TypeDescription typeDescription,
         DynamicType.Builder<?> newClassBuilder, ClassLoader classLoader,
         EnhanceContext context) throws PluginException {
@@ -174,6 +175,7 @@ public abstract class ClassEnhancePluginDefine extends AbstractClassEnhancePlugi
      * @param newClassBuilder byte-buddy's builder to manipulate class bytecode.
      * @return new byte-buddy's builder for further manipulation.
      */
+    @Override
     protected DynamicType.Builder<?> enhanceClass(TypeDescription typeDescription, DynamicType.Builder<?> newClassBuilder,
         ClassLoader classLoader) throws PluginException {
         StaticMethodsInterceptPoint[] staticMethodsInterceptPoints = getStaticMethodsInterceptPoints();
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/v2/ClassEnhancePluginDefineV2.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/v2/ClassEnhancePluginDefineV2.java
index ff26034f5..733d32f18 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/v2/ClassEnhancePluginDefineV2.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/v2/ClassEnhancePluginDefineV2.java
@@ -56,6 +56,7 @@ import static net.bytebuddy.matcher.ElementMatchers.not;
  */
 public abstract class ClassEnhancePluginDefineV2 extends AbstractClassEnhancePluginDefine {
 
+    @Override
     protected DynamicType.Builder<?> enhanceClass(TypeDescription typeDescription,
                                                   DynamicType.Builder<?> newClassBuilder,
                                                   ClassLoader classLoader) throws PluginException {
@@ -105,6 +106,7 @@ public abstract class ClassEnhancePluginDefineV2 extends AbstractClassEnhancePlu
         return newClassBuilder;
     }
 
+    @Override
     protected DynamicType.Builder<?> enhanceInstance(TypeDescription typeDescription,
                                                      DynamicType.Builder<?> newClassBuilder, ClassLoader classLoader,
                                                      EnhanceContext context) throws PluginException {